1 /*
2 * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24 import static java.io.File.createTempFile;
25 import static java.lang.Long.parseLong;
26 import static java.lang.System.getProperty;
27 import static java.nio.file.Files.readAllBytes;
28 import static java.util.Arrays.stream;
29 import static java.util.stream.Collectors.joining;
30 import static java.util.stream.Collectors.toList;
31 import static jdk.test.lib.process.ProcessTools.createJavaProcessBuilder;
32 import static jdk.test.lib.Platform.isWindows;
33
34 import java.io.BufferedReader;
35 import java.io.File;
36 import java.io.FileNotFoundException;
37 import java.io.FileOutputStream;
38 import java.io.IOException;
39 import java.io.InputStreamReader;
40 import java.util.Collection;
41 import java.util.Optional;
42 import java.util.stream.Stream;
43
44 /*
45 * @test TestInheritFD
46 * @bug 8176717 8176809
47 * @summary a new process should not inherit open file descriptors
48 * @library /test/lib
49 * @modules java.base/jdk.internal.misc
50 * java.management
51 */
52
53 /**
54 * Test that HotSpot does not leak logging file descriptors.
55 *
56 * This test is performed in three steps. The first VM starts a second VM with
57 * gc logging enabled. The second VM starts a third VM and redirects the third
58 * VMs output to the first VM, it then exits and hopefully closes its log file.
59 *
60 * The third VM waits for the second to exit and close its log file. After that,
61 * the third VM tries to rename the log file of the second VM. If it succeeds in
62 * doing so it means that the third VM did not inherit the open log file
63 * (windows can not rename opened files easily)
64 *
65 * The third VM communicates the success to rename the file by printing "CLOSED
66 * FD". The first VM checks that the string was printed by the third VM.
67 *
68 * On unix like systems "lsof" or "pfiles" is used.
69 */
70
71 public class TestInheritFD {
72
73 public static final String LEAKS_FD = "VM RESULT => LEAKS FD";
74 public static final String RETAINS_FD = "VM RESULT => RETAINS FD";
75 public static final String EXIT = "VM RESULT => VM EXIT";
76 public static final String LOG_SUFFIX = ".strangelogsuffixthatcanbecheckedfor";
77
78 // first VM
79 public static void main(String[] args) throws Exception {
80 String logPath = createTempFile("logging", LOG_SUFFIX).getName();
81 File commFile = createTempFile("communication", ".txt");
82
83 if (!isWindows() && !lsofCommand().isPresent()) {
84 System.out.println("Could not find lsof like command");
85 System.out.println("Exit test case as successful though it could not verify anything");
86 return;
87 }
88
89 ProcessBuilder pb = createJavaProcessBuilder(
90 "-Xlog:gc:\"" + logPath + "\"",
91 "-Dtest.jdk=" + getProperty("test.jdk"),
92 VMStartedWithLogging.class.getName(),
93 logPath);
94
95 pb.redirectOutput(commFile); // use temp file to communicate between processes
96 pb.start();
97
98 String out = "";
99 do {
100 out = new String(readAllBytes(commFile.toPath()));
101 Thread.sleep(100);
102 System.out.println("SLEEP 100 millis");
103 } while (!out.contains(EXIT));
104
105 System.out.println(out);
106 if (out.contains(RETAINS_FD)) {
107 System.out.println("Log file was not inherited by third VM");
108 } else {
109 throw new RuntimeException("could not match: " + RETAINS_FD);
110 }
111 }
112
113 static class VMStartedWithLogging {
114 // second VM
115 public static void main(String[] args) throws IOException, InterruptedException {
116 ProcessBuilder pb = createJavaProcessBuilder(
117 "-Dtest.jdk=" + getProperty("test.jdk"),
118 VMShouldNotInheritFileDescriptors.class.getName(),
119 args[0],
120 "" + ProcessHandle.current().pid());
121 pb.inheritIO(); // in future, redirect information from third VM to first VM
122 pb.start();
123
124 if (!isWindows()) {
125 System.out.println("(Second VM) Open file descriptors:\n" + outputContainingFilenames().stream().collect(joining("\n")));
126 }
127 }
128 }
129
130 static class VMShouldNotInheritFileDescriptors {
131 // third VM
132 public static void main(String[] args) throws InterruptedException {
133 try {
134 File logFile = new File(args[0]);
135 long parentPid = parseLong(args[1]);
136 fakeLeakyJVM(false); // for debugging of test case
137
138 if (isWindows()) {
139 windows(logFile, parentPid);
140 } else {
141 Collection<String> output = outputContainingFilenames();
142 System.out.println("(Third VM) Open file descriptors:\n" + output.stream().collect(joining("\n")));
143 System.out.println(findOpenLogFile(output) ? LEAKS_FD : RETAINS_FD);
144 }
145 } catch (Exception e) {
146 System.out.println(e.toString());
147 } finally {
148 System.out.println(EXIT);
149 }
150 }
151 }
152
153 // for debugging of test case
154 @SuppressWarnings("resource")
155 static void fakeLeakyJVM(boolean fake) {
156 if (fake) {
157 try {
158 new FileOutputStream("fakeLeakyJVM" + LOG_SUFFIX, false);
159 } catch (FileNotFoundException e) {
160 }
161 }
162 }
163
164 static Stream<String> run(String... args){
165 try {
166 return new BufferedReader(new InputStreamReader(new ProcessBuilder(args).start().getInputStream())).lines();
167 } catch (IOException e) {
168 throw new RuntimeException(e);
169 }
170 }
171
172 static Optional<String[]> lsofCommandCache = stream(new String[][]{
173 {"/usr/bin/lsof", "-p"},
174 {"/usr/sbin/lsof", "-p"},
175 {"/bin/lsof", "-p"},
176 {"/sbin/lsof", "-p"},
177 {"/usr/local/bin/lsof", "-p"},
178 {"/usr/bin/pfiles", "-F"}}) // Solaris
179 .filter(args -> new File(args[0]).exists())
180 .findFirst();
181
182 static Optional<String[]> lsofCommand() {
183 return lsofCommandCache;
184 }
185
186 static Collection<String> outputContainingFilenames() {
187 long pid = ProcessHandle.current().pid();
188
189 String[] command = lsofCommand().orElseThrow(() -> new RuntimeException("lsof like command not found"));
190 System.out.println("using command: " + command[0] + " " + command[1]);
191 return run(command[0], command[1], "" + pid).collect(toList());
192 }
193
194 static boolean findOpenLogFile(Collection<String> fileNames) {
195 return fileNames.stream()
196 .filter(fileName -> fileName.contains(LOG_SUFFIX))
197 .findAny()
198 .isPresent();
199 }
200
201 static void windows(File f, long parentPid) throws InterruptedException {
202 System.out.println("waiting for pid: " + parentPid);
203 ProcessHandle.of(parentPid).ifPresent(handle -> handle.onExit().join());
204 System.out.println("trying to rename file to the same name: " + f);
205 System.out.println(f.renameTo(f) ? RETAINS_FD : LEAKS_FD); // this parts communicates a closed file descriptor by printing "VM RESULT => RETAINS FD"
206 }
207 }
208